Healthy Lunch Ideas

I'm looking for some ideas on cheap food options that can provide lunch for me for multiple days.

So I work out over lunch and then eat at my desk every day after I'm finished. I did frozen meals for a long time and got totally burned out on them...plus we all know they aren't the best source of nutrition. Lately I've been doing a Quizno's or Subway sandwich and chips for lunch. I don't mind doing so but that can get expensive and I'm looking for some healthier and more balanced options that will make food for more than one day.

I know a guy at the gym that bakes a bunch of chicken breasts at the beginning of the week and then mixes it with some pasta. He just keeps it all in a huge container and takes out a reasonable portion each day for lunch. It is cheap, quick, and something that doesn't take making a good choice each day. Something along those lines would be good, but I didn't think pasta every day would be the best choice.

Any suggestions on specific meals that will fit this category and how to prepare them?

Thank you!